As reported last year, NADH fluorometry was carried out over the exposed cat cortex during reticulo-cortical activation. Reflected ultraviolet light (UV), which was used as a reference for NADH, was found to be unreliable because of motion-induced specular UV changes during large increases in cortical blood flow. Sodium fluorescein fluorescence was substituted as a reference signal. NADH oxidation was then studied over various cortical areas during brain stem stimulation and Metrazol- induced seizures.